chore: add example usage of extending cluster and node security group access rules (#1805)

examples/self_managed_node_group/main.tf

@@ -48,6 +48,39 @@ module "eks" {
 
   enable_irsa = true
 
+  # Extend cluster security group rules
+  cluster_security_group_additional_rules = {
+    egress_nodes_ephemeral_ports_tcp = {
+      description                = "To node 1025-65535"
+      protocol                   = "tcp"
+      from_port                  = 1025
+      to_port                    = 65535
+      type                       = "egress"
+      source_node_security_group = true
+    }
+  }
+
+  # Extend node-to-node security group rules
+  node_security_group_additional_rules = {
+    ingress_self_all = {
+      description = "Node to node all ports/protocols"
+      protocol    = "-1"
+      from_port   = 0
+      to_port     = 0
+      type        = "ingress"
+      self        = true
+    }
+    egress_all = {
+      description      = "Node all egress"
+      protocol         = "-1"
+      from_port        = 0
+      to_port          = 0
+      type             = "egress"
+      cidr_blocks      = ["0.0.0.0/0"]
+      ipv6_cidr_blocks = ["::/0"]
+    }
+  }
+
   self_managed_node_group_defaults = {
     disk_size = 50
   }